Posts Tagged ‘solar

A study funded by NASA has flagged up yet another terrible hazard for those no longer able to get excited about nuclear war, global pandemics, terrorism, climate change, economic meltdown and asteroid strike. Top space brainboxes say that even if the human race survives all those, there is a serious risk of civilisation being brought crashing to its knees by a sudden high-intensity solar radiation storm.

In essence, the report, which can be downloaded in pdf here (free registration required) says that sooner or later there will be a solar storm much more powerful than any seen so far in the age of high technology. Such events have occurred in the past, but as the human race then had very basic electrical power grids (or none at all) and made no use of satellites, it didn’t matter.

The next space radiation biggy, however, will hit a human civilisation which is becoming more and more dependent on satellites for essential communication and navigation tasks, and whose electrical grids are much more widespread and heavily stressed. The impact of a bad geomagnetic spike would be somewhat as though an unbelievably powerful electromagnetic pulse bomb – of the sort favoured by movie villains but not yet available – had gone off:

While a severe storm is a low-frequency-of-occurrence event, it has the potential for long-duration catastrophic impacts to the power grid and its users. Impacts would be felt on interdependent infrastructures, with, for example, potable water distribution affected within several hours; perishable foods and medications lost in about 12-24 hours; and immediate or eventual loss of heating/air conditioning, sewage disposal, phone service, transportation, fuel resupply, and so on …Open access on the transmission system has fostered the transport of large amounts of energy across the power system in order to maximize the economic benefit of delivering the lowest-cost energy to areas of demand. The magnitude of power transfers has grown, and the risk is that the increased level of transfers, coupled with multiple equipment failures, could worsen the impacts of a storm event …

In summary, present U.S. grid operational procedures … are unlikely to be adequate for historically large disturbance events.

The impact on satellites would be even more severe, as spacecraft have less shielding from the Earth’s atmosphere – and in some cases from the magnetosphere. In particular, the present Global Positioning System (GPS) sat constellation, used by almost every navigation system in the world, is regarded as highly vulnerable to a solar event – though new satellites are to go up shortly equipped with a backup signal which will allow errors to be bowled out.

In general, however, the assembled brainboxes considered that a solar event was a much greater threat to essential space infrastructure than any evil foreign power – for instance – could possibly be. The US military has previously warned of the risk of a “space Pearl Harbour” – a devastating surprise attack against America’s space presence, which could leave the world’s sole superpower blinded and crippled. According to the National Academy, though, the USA should forget about a space Pearl Harbour and worry instead about “a space Katrina, a storm that we should have been prepared for but were not”.

“It’s called a flux transfer event or ‘FTE,'” says space physicist David Sibeck of the Goddard Space Flight Center. “Ten years ago I was pretty sure they didn’t exist, but now the evidence is incontrovertible.”

Researchers have long known that the Earth and sun must be connected. Earth’s magnetosphere (the magnetic bubble that surrounds our planet) is filled with particles from the sun that arrive via the solar wind and penetrate the planet’s magnetic defenses. They enter by following magnetic field lines that can be traced from terra firma all the way back to the sun’s atmosphere.

“We used to think the connection was permanent and that solar wind could trickle into the near-Earth environment anytime the wind was active,” says Sibeck. “We were wrong. The connections are not steady at all. They are often brief, bursty and very dynamic.”

There are many unanswered questions: Why do the portals form every 8 minutes? How do magnetic fields inside the cylinder twist and coil?

At the focal point, solar furnaces can achieve temperatures of 5,430 ºF (3,000 ºC). The idea is not new—coming from ancient Greece—but their potential is starting to become more relevant now as we try to cut dependency on fossil fuels.

solar power is a relatively untapped energy which is abundant. with recent developments in the manufacturing of the collectors, like nanosolar, perhaps there is hope we can figure out cheap/open solar systems.

Sept. 30, 2008: Astronomers who count sunspots have announced that 2008 is now the “blankest year” of the Space Age.

As of Sept. 27, 2008, the sun had been blank, i.e., had no visible sunspots, on 200 days of the year. To find a year with more blank suns, you have to go back to 1954, three years before the launch of Sputnik, when the sun was blank 241 times.

“Sunspot counts are at a 50-year low,” says solar physicist David Hathaway of the NASA Marshall Space Flight Center. “We’re experiencing a deep minimum of the solar cycle.”

A spotless day looks like this:

The image, taken by the Solar and Heliospheric Observatory (SOHO) on Sept. 27, 2008, shows a solar disk completely unmarked by sunspots. For comparison, a SOHO image taken seven years earlier on Sept. 27, 2001, is peppered with colossal sunspots, all crackling with solar flares: image. The difference is the phase of the 11-year solar cycle. 2001 was a year of solar maximum, with lots of sunspots, solar flares and geomagnetic storms. 2008 is at the cycle’s opposite extreme, solar minimum, a quiet time on the sun.

And it is a very quiet time. If solar activity continues as low as it has been, 2008 could rack up a whopping 290 spotless days by the end of December, making it a century-level year in terms of spotlessness.

Hathaway cautions that this development may sound more exciting than it actually is: “While the solar minimum of 2008 is shaping up to be the deepest of the Space Age, it is still unremarkable compared to the long and deep solar minima of the late 19th and early 20th centuries.” Those earlier minima routinely racked up 200 to 300 spotless days per year.

As an example he offers helioseismology: “By monitoring the sun’s vibrating surface, helioseismologists can probe the stellar interior in much the same way geologists use earthquakes to probe inside Earth. With sunspots out of the way, we gain a better view of the sun’s subsurface winds and inner magnetic dynamo.”

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“There is also the matter of solar irradiance,” adds Pesnell. “Researchers are now seeing the dimmest sun in their records. The change is small, just a fraction of a percent, but significant. Questions about effects on climate are natural if the sun continues to dim.”

Coinciding with the string of blank suns is a 50-year record low in solar wind pressure, a recent discovery of the Ulysses spacecraft. (See the Science@NASA story Solar Wind Loses Pressure.) The pressure drop began years before the current minimum, so it is unclear how the two phenomena are connected, if at all. This is another mystery for SDO and the others.